crypto: hisilicon/qm - fix the call trace when unbind device

Call trace will appear in the Hisilicon crypto driver unbinding or
disabling SRIOV during task running with TFMs on the corresponding
function.
The log looks like this:
	[  293.908078] Call trace:
	[  293.908080]  __queue_work+0x494/0x548
	[  293.908081]  queue_work_on+0x84/0xd8
	[  293.908092]  qm_irq+0x4c/0xd0 [hisi_qm]
	[  293.908096]  __handle_irq_event_percpu+0x74/0x2a0
	[  293.908098]  handle_irq_event_percpu+0x40/0x98
	[  293.908099]  handle_irq_event+0x4c/0x80
	[  293.908101]  handle_fasteoi_irq+0xb0/0x170
	[  293.908102]  generic_handle_irq+0x3c/0x58
	[  293.908103]  __handle_domain_irq+0x68/0xc0
	[  293.908104]  gic_handle_irq+0xb4/0x298
	[  293.908105]  el1_irq+0xcc/0x180
	[  293.908107]  arch_cpu_idle+0x38/0x228
	[  293.908110]  default_idle_call+0x20/0x40
	[  293.908113]  do_idle+0x1cc/0x2b8
	[  293.908114]  cpu_startup_entry+0x2c/0x30
	[  293.908115]  rest_init+0xdc/0xe8
	[  293.908117]  arch_call_rest_init+0x14/0x1c
	[  293.908117]  start_kernel+0x490/0x4c4

This patch adds a waiting logic as user doing the above two operations
to avoid panic. The two operations will hold on in the driver
remove function until the tasks release all their relative TFMs.

Signed-off-by: Hui Tang <tanghui20@huawei.com>
Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Reviewed-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 90 insertions, 5 deletions

diff --git a/drivers/crypto/hisilicon/qm.c b/drivers/crypto/hisilicon/qm.c
index f2729e6db920..50a0e66baf8b 100644
--- a/drivers/crypto/hisilicon/qm.c
+++ b/drivers/crypto/hisilicon/qm.c
@@ -180,6 +180,8 @@
 #define QM_DBG_TMP_BUF_LEN		22
 #define QM_PCI_COMMAND_INVALID		~0
 
+#define WAIT_PERIOD			20
+#define REMOVE_WAIT_DELAY		10
 #define QM_SQE_ADDR_MASK		GENMASK(7, 0)
 #define QM_EQ_DEPTH			(1024 * 2)
 
@@ -2225,6 +2227,82 @@ static int qm_alloc_uacce(struct hisi_qm *qm)
 }
 
 /**
+ * qm_frozen() - Try to froze QM to cut continuous queue request. If
+ * there is user on the QM, return failure without doing anything.
+ * @qm: The qm needed to be fronzen.
+ *
+ * This function frozes QM, then we can do SRIOV disabling.
+ */
+static int qm_frozen(struct hisi_qm *qm)
+{
+	down_write(&qm->qps_lock);
+
+	if (qm->is_frozen) {
+		up_write(&qm->qps_lock);
+		return 0;
+	}
+
+	if (!qm->qp_in_used) {
+		qm->qp_in_used = qm->qp_num;
+		qm->is_frozen = true;
+		up_write(&qm->qps_lock);
+		return 0;
+	}
+
+	up_write(&qm->qps_lock);
+
+	return -EBUSY;
+}
+
+static int qm_try_frozen_vfs(struct pci_dev *pdev,
+			     struct hisi_qm_list *qm_list)
+{
+	struct hisi_qm *qm, *vf_qm;
+	struct pci_dev *dev;
+	int ret = 0;
+
+	if (!qm_list || !pdev)
+		return -EINVAL;
+
+	/* Try to frozen all the VFs as disable SRIOV */
+	mutex_lock(&qm_list->lock);
+	list_for_each_entry(qm, &qm_list->list, list) {
+		dev = qm->pdev;
+		if (dev == pdev)
+			continue;
+		if (pci_physfn(dev) == pdev) {
+			vf_qm = pci_get_drvdata(dev);
+			ret = qm_frozen(vf_qm);
+			if (ret)
+				goto frozen_fail;
+		}
+	}
+
+frozen_fail:
+	mutex_unlock(&qm_list->lock);
+
+	return ret;
+}
+
+/**
+ * hisi_qm_wait_task_finish() - Wait until the task is finished
+ * when removing the driver.
+ * @qm: The qm needed to wait for the task to finish.
+ * @qm_list: The list of all available devices.
+ */
+void hisi_qm_wait_task_finish(struct hisi_qm *qm, struct hisi_qm_list *qm_list)
+{
+	while (qm_frozen(qm) ||
+	       ((qm->fun_type == QM_HW_PF) &&
+	       qm_try_frozen_vfs(qm->pdev, qm_list))) {
+		msleep(WAIT_PERIOD);
+	}
+
+	udelay(REMOVE_WAIT_DELAY);
+}
+EXPORT_SYMBOL_GPL(hisi_qm_wait_task_finish);
+
+/**
  * hisi_qm_get_free_qp_num() - Get free number of qp in qm.
  * @qm: The qm which want to get free qp.
  *
@@ -2348,6 +2426,7 @@ static void hisi_qm_pre_init(struct hisi_qm *qm)
 	mutex_init(&qm->mailbox_lock);
 	init_rwsem(&qm->qps_lock);
 	qm->qp_in_used = 0;
+	qm->is_frozen = false;
 }
 
 /**
@@ -3093,11 +3172,12 @@ EXPORT_SYMBOL_GPL(hisi_qm_sriov_enable);
 
 /**
  * hisi_qm_sriov_disable - disable virtual functions
- * @pdev: the PCI device
+ * @pdev: the PCI device.
+ * @is_frozen: true when all the VFs are frozen.
  *
- * Return failure if there are VFs assigned already.
+ * Return failure if there are VFs assigned already or VF is in used.
  */
-int hisi_qm_sriov_disable(struct pci_dev *pdev)
+int hisi_qm_sriov_disable(struct pci_dev *pdev, bool is_frozen)
 {
 	struct hisi_qm *qm = pci_get_drvdata(pdev);
 
@@ -3106,7 +3186,12 @@ int hisi_qm_sriov_disable(struct pci_dev *pdev)
 		return -EPERM;
 	}
 
-	/* remove in hpre_pci_driver will be called to free VF resources */
+	/* While VF is in used, SRIOV cannot be disabled. */
+	if (!is_frozen && qm_try_frozen_vfs(pdev, qm->qm_list)) {
+		pci_err(pdev, "Task is using its VF!\n");
+		return -EBUSY;
+	}
+
 	pci_disable_sriov(pdev);
 	return qm_clear_vft_config(qm);
 }
@@ -3122,7 +3207,7 @@ EXPORT_SYMBOL_GPL(hisi_qm_sriov_disable);
 int hisi_qm_sriov_configure(struct pci_dev *pdev, int num_vfs)
 {
 	if (num_vfs == 0)
-		return hisi_qm_sriov_disable(pdev);
+		return hisi_qm_sriov_disable(pdev, 0);
 	else
 		return hisi_qm_sriov_enable(pdev, num_vfs);
 }